MRI: Acquisition of an All Digital Multiparameter Gamma Spectroscopy System for Research and Research Training in Nuclear Physics

弱相互作用是自然界的四种基本力量之一，它导致了一种被称为贝塔衰变的放射性衰变。对β衰变的精确测量可以探索我们对弱相互作用的理解极限，在探索新物理的过程中补充粒子对撞机实验，同时成本要低得多。国家超导回旋加速器实验室等可产生各种放射性同位素束流的设施最近的发展为改进贝塔衰变测量创造了新的机会。要充分开发这些新同位素的潜力，需要对各种类型的粒子探测器的响应有很好的了解。了解粒子探测器的响应对于国土安全、核安全和医学方面的许多应用也很重要。通过这笔赠款获得的仪器将能够在广泛的能量范围内测量各种粒子探测器对新的精度水平的反应。在粒子相互作用的标准模型之外，精确测量核β衰变的光谱形状对物理很敏感。最近强大的放射性束流设施的发展为改进核β谱形状的测量创造了新的机会，方法是将核植入完全包含发射粒子的探测器中。在理想的情况下，这提供了许多系统的测量，而不是更传统的贝塔光谱学所受的影响。然而，充分开发新探测器方法的潜力需要对植入探测器响应的精确知识。这一探测器响应特性是拟议收购全数字多参数伽马光谱分析系统所能实现的主要研究。表征的基础是广角康普顿符合技术。这项技术使用康普顿散射与中等强度的标准伽马源来表征基本上任何探测器材料相对于例如高纯度锗探测器的能量相关电子响应。根据这一提议获得的系统将使测量各种探测器的非线性度达到新的精度水平，并在比目前存在的更宽的能量范围内进行测量。

The weak interaction, one of the four fundamental forces of nature, is responsible for the type of radioactive decay called beta decay. Precise measurements of beta decay can probe the limits of our understanding of the weak interaction, complementing particle collider experiments in the search for new physics while being much less costly. The recent development of facilities, such as at the National Superconducting Cyclotron Laboratory, that can produce a variety of beams of radioactive isotopes has created new opportunities for improved beta decay measurements. To fully exploit the potential of these new isotopes requires a good understanding of the response of various types of particle detectors. Understanding the response of particle detectors is also important for many applications in homeland security, nuclear safeguards, and medicine. The instrument to be acquired through this grant will enable the measurement of the response of a variety of particle detectors to a new level of precision over a wide energy range. Precise measurements of the shapes of spectra in nuclear beta decay are sensitive to physics beyond the Standard Model of particle interactions. The recent development of powerful radioactive beam facilities has created a new opportunity for improved measurements of nuclear beta spectrum shapes through implantation of the nuclei in detectors that fully contain the emitted particles. In the ideal case, this provides measurements free of many of the systematic effects more conventional beta spectroscopy is subject to. Fully exploiting the potential of the new detector method, however, requires precise knowledge of implantation detector response. This detector response characterization is the primary research to be enabled by the proposed acquisition of an all-digital multi-parameter gamma spectroscopy system. The basis of the characterizations is the Wide Angle Compton Coincidence technique. This technique uses Compton scattering with standard gamma sources of modest strength to characterize the energy dependent electron response of essentially any detector material relative to, for example, a High Purity Germanium detector. The system acquired under this proposal will enable the measurement of the nonlinearity of a wide variety of detectors to a new level of precision and over a wider energy range than presently exists.